The present invention relates to a turn indicator system for use in automobiles.
Generally, an automobile has a turn indicator system including a turn indicator lever provided at a position within reach of a driver and adjacent, for example, a steering wheel, for tilting or pivotal movement in a clockwise or counterclockwise direction from a neutral position, a switch unit provided in association with the turn indicator lever, and right and left indicator lamps, the right indicator lamp or lamps being actuated to blink when the turn indicator lever is tilted clockwise, and the left indicator lamp or lamps being actuated to blink when the turn indicator lever is tilted counterclockwise.
The turn indicator system of the above described typical arrangement further includes an automatic cancellation mechanism provided in association with the steering wheel to automatically turn the tilted indicator lever to the neutral position after the completion of turning movement of the automobile.
According to the prior art turn indicator system, the automatic cancellation mechanism returns the turn indicator lever to the neutral position when the steering wheel is turned in a direction opposite to the direction in which the indicator lever has been tilted. (It is to be noted that the direction of rotation of the steering wheel in the direction in which the indicator lever is tilted will hereinafter be referred to as "indicated direction" and that the term "counterindicated direction" herein used is to be understood as meaning the direction opposite to the indicated direction.) For example, when the turn indicator lever is tilted clockwise, it is held in the tilted position during the clockwise rotation of the steering wheel, but is returned to the neutral position by the automatic cancellation mechanism when the steering wheel is turned counterclockwise.
In the prior art turn indicator system of the type described above, there is such a disadvantage that the turn indicator lever will unnecessarily be returned to the neutral position when the steering wheel is turned a slight angle in the counterindicated direction, i.e., a direction opposite to the direction of turn of the automobile, before the steering wheel is completely in the direction of turn of the automobile, that is, before the automobile completes the turn in the intended direction. By way of example, assuming that the driver has tilted the indicator lever clockwise in an attempt to turn the automobile rightwards and the rightward turn indicator lamp has accordingly been actuated to blink, and assuming that the driver who should turn the steering wheel clockwise to turn the automobile rightwards is forced to turn the automobile slightly leftwards for avoiding an obstacle on its way or for some other reason by turning the steering wheel counterclockwise through a slight angle, such a counterclockwise turn of the steering wheel through the slight angle causes the cancellation mechanism to return the once-tilted indicator lever to the neutral position with the result that the rightward turn indicator lamp is consequently deenergized. Accordingly, the driver must again tilt the indicator lever clockwise if and when he wishes to complete the rightward turn of the automobile after having avoided the obstacle.
Furthermore, the size of the turn indicator system of the prior art is considerably large since the arrangement for automatic cancellation is constituted by a mechanical arrangement.